Sensor array

ABSTRACT

In one illustrative embodiment, a test strip with a first planar substrate has coplanar electrodes on a first planar surface and a second planar substrate (which opposes the first surface of the first planar substrate) has coplanar electrodes on a second planar surface. The first planar surface of the first planar substrate having a first sensing area electrically connected to a first electrical contact. The second planar surface of the second planar substrate having a second electrical contact electrically connected to the first electrical contact via a conductive element, the conductive element extending between the first surface of the first planar substrate and the second surface of the second planar substrate without passing through the first planar substrate, the second planar substrate, or any intermediate layers.

This is a continuation application of U.S. Ser. No. 15/325,307, filedJan. 10, 2017 which claims the benefit of US National Stage ofInternational Application No. PCT/US2015/040837, filed Jul. 17, 2015 andclaims priority under 35 U.S.C. 119(e) to U.S. Provisional ApplicationNo. 62/025,632, filed Jul. 17, 2014. All of the applications areincorporated by reference herein in their entirety.

BACKGROUND

This disclosure relates to a sensing device which allows for multipletests to be run concurrently using a small sample volume.

SUMMARY OF THE INVENTIVE CONCEPT(S)

In one illustrative embodiment, the inventive concepts disclosed hereinare directed to a test strip with a first planar substrate withelectrodes on a first planar surface and a second planar substrate withcoplanar electrodes on a second planar surface. The first planarsubstrate and the second planar substrate are arranged such that thefirst surface of the first planar substrate opposes the second planarsurface of the second planar substrate. The test strips also contains anintermediate layer(s) disposed in between the opposed first surface ofthe first planar substrate and the second planar surface of the secondplanar substrate. The first planar surface of the first planar substratehaving a first sensing area electrically connected to a first electricalcontact. The second planar surface of the second planar substrate havinga second electrical contact electrically connected to the firstelectrical contact via a conductive element, the conductive elementextending between the first surface of the first planar substrate andthe second surface of the second planar substrate without passingthrough the first planar substrate or the second planar substrate.

BRIEF DESCRIPTIONS OF THE DRAWINGS

FIG. 1 depicts an exploded view of one embodiment of the test strip.

FIG. 2 depicts a top view of test strip of one embodiment of the teststrip.

FIG. 3 depicts a side view of one embodiment of the test strip.

FIG. 4 depicts an exploded view of a second embodiment of the teststrip.

FIG. 5 depicts a top view of test strip of the second embodiment of thetest strip.

FIG. 6 depicts a side view of the second embodiment of the test strip.

FIG. 7 depicts a side view of a third embodiment of a test strip.

DETAILED DESCRIPTION OF THE INVENTIVE CONCEPT(S)

Before explaining at least one embodiment of the inventive conceptsdisclosed herein in detail, it is to be understood that the inventiveconcepts are not limited in their application to the details ofconstruction and the arrangement of the components or steps ormethodologies set forth in the following description or illustrated inthe drawings. The inventive concepts disclosed herein are capable ofother embodiments or of being practiced or carried out in various ways.Also, it is to be understood that the phraseology and terminologyemployed herein is for the purpose of description and should not beregarded as limiting the inventive concepts disclosed and claimed hereinin any way.

In the following detailed description of embodiments of the inventiveconcepts, numerous specific details are set forth in order to provide amore thorough understanding of the inventive concepts. However, it willbe apparent to one of ordinary skill in the art that the inventiveconcepts within the instant disclosure may be practiced without thesespecific details. In other instances, well-known features have not beendescribed in detail to avoid unnecessarily complicating the instantdisclosure.

As used herein, the terms “comprises,” “comprising,” “includes,”“including,” “has,” “having” or any other variation thereof, areintended to cover a non-exclusive inclusion. For example, a composition,a process, method, article, or apparatus that comprises a list ofelements is not necessarily limited to only those elements but mayinclude other elements not expressly listed or inherently presenttherein.

As used herein the terms “approximately,” “about,” “substantially” andvariations thereof are intended to include not only the exact valuequalified by the term, but to also include some slight deviationstherefrom, such as deviations caused by measuring error, manufacturingtolerances, wear and tear on components or structures, settling orprecipitation of cells or particles out of suspension or solution,chemical or biological degradation of solutions over time, stressexerted on structures, and combinations thereof, for example.

As used herein, the term “sample” and variations thereof is intended toinclude biological tissues, biological fluids, chemical fluids, chemicalsubstances, suspensions, solutions, slurries, mixtures, agglomerations,tinctures, slides, powders, or other preparations of biological tissuesor fluids, synthetic analogs to biological tissues or fluids, bacterialcells (prokaryotic or eukaryotic), viruses, single-celled organisms,lysed biological cells, fixed biological cells, fixed biologicaltissues, cell cultures, tissue cultures, genetically engineered cellsand tissues, genetically engineered organisms, and combinations thereof,for example.

Unless expressly stated to the contrary, “or” refers to an inclusive orand not to an exclusive or. For example, a condition A or B is satisfiedby anyone of the following: A is true (or present) and B is false (ornot present), A is false (or not present) and B is true (or present),and both A and B are true (or present). An inclusive or may beunderstood as being the equivalent to: at least one of condition A or B.

In addition, use of the “a” or “an” are employed to describe elementsand components of the embodiments herein. This is done merely forconvenience and to give a general sense of the inventive concepts. Thisdescription should be read to include one or at least one and thesingular also includes the plural unless it is obvious that it is meantotherwise.

Finally, as used herein any reference to “one embodiment” or “anembodiment” means that a particular element, feature, structure, orcharacteristic described in connection with the embodiment is includedin at least one embodiment. The appearances of the phrase “in oneembodiment” in various places in the specification are not necessarilyall referring to the same embodiment.

The inventive concepts disclosed herein are generally directed to theneed to minimize the sample volume required to test two or more analytesconcurrently. Low sample volumes are desirable when the sample islimited, such as in the case of neonatal patients, or when the sampleitself is expensive. As opposed to prior art test strip configurations,which required the volume to increase with the number of analytes beingdetected, the required sample volume can be greatly reduced when thesensors are arranged in such a way that they are facing one another in asandwich configuration (also referred to as an opposing sensor array)rather than in a coplanar configuration. However, in order to simplifythe manner in which test strips with opposing sensor arrays interfacewith medical instruments, respective sensors can be electricallyconnected to coplanar (e.g., same side) contacts. This configurationmaximizes the number of sensors that can be incorporated into a singletest strip while simplifying the manner in which the strip interfaceswith the medical instrument. Illustrative embodiments of opposing sensorarrays with coplanar contacts are discussed in connection with FIGS. 1through 7 below.

FIGS. 1-3 depict illustrative test strip 100. FIG. 1 depicts an explodedview of each layer of test strip 100. FIG. 2 depicts a top view of teststrip 100. FIG. 3 depicts a side view of test strip 100 along line A-A′.

Test strip 100 contains a first planar substrate 2 with coplanarelectrodes 4 on a first planar surface 6 and a second planar substrate 8with coplanar electrodes 10 on a second planar surface 12. The firstplanar substrate 2 and the second planar substrate 8 are arranged suchthat the first surface 6 of the first planar substrate 2 opposes (i.e.,is opposite) the second planar surface 12 of the second planar substrate8. In this opposed configuration, the first planar surface 6 as well asthe coplanar electrodes 4 disposed thereon face the second planarsurface 12 and the coplanar electrodes 10 disposed thereon. Stateddifferently, the second planar substrate 8 is disposed below the firstplanar substrate 2 along a line extending from the first planar surface6 of the first planar substrate 2 to the second planar surface 12 of thefirst planar substrate 2.

Planar substrates 2 and 8 may be formed using a variety of methods andmaterials known to a person of ordinary skill in the art. For example,planar substrates 2 and 8 may be flexible or rigid and may beconstructed using, for example, standard PCB, flex PCB, PET, PI,ceramic, glass, etc.

Coplanar electrodes 4 and 10 may be formed using a variety of methodsand materials known to a person of ordinary skill in the art. Forexample, coplanar electrodes 4 and 10 may be formed using a thick filmapproach (e.g., screen printing, rotogravure, pad printing, stenciling,ink jetting or aerosol jetting conductive material such as carbon, Cu,Pt, Pd, Au, and/or Nanotubes (such as carbon nanotubes), etc. . . . ) ora thin film approach (e.g., by sputtering, thermal spraying, and/or coldspraying conductive material). Coplanar electrodes 4 and 10,respectively, may be partitioned using, for example, laser ablation. Itshould be understood that the configuration of electrodes 4, 10 depictedherein are merely for illustrative purposes only and a person ofordinary skill in the art will appreciate that electrodes 4, 10 may bedistributed on substrates 2, 8 in a variety of ways. As will beappreciated by those skilled in the art, the term “coplanar,” as usedherein to describe electrodes 4 and 10, should be understood asencompassing those electrodes which are substantially coplanar (as wellas those which are fully co planar. Thus, individual electrodes can beslightly raised, recessed, and/or angled as compared other coplanarelectrodes 4 and 10 on planar substrates 2 and 8, respectively, andstill be considered coplanar.

One or more planar intermediate layers 14 can be disposed in between theopposed first planar surface 6 of the first planar substrate 2 and thesecond planar surface 12 of the second planar substrate 8. Theintermediate layer(s) 14 may be formed using a variety of methods andmaterials known to a person of ordinary skill in the art. For example,intermediate layers 14 may be made out of an inert substrate such as adielectric, pressure sensitive adhesive, laminate, etc. . . . .Alternatively, intermediate layers 14 can be integrated into planarsubstrates 2, 8, respectively, by forming intermediate layer(s) 14directly on top of surfaces 6, 12 and coplanar electrodes 4, 10. One ormore of intermediate layer(s) 14 can be an isolating layer(s) made froma dielectric or insulating material which isolates one or more, up toall, of electrodes 4 and electrodes 10 from one another. Alternatively,intermediate layers 14 can provide conductive pathways which allow oneor more of electrodes 4 and one or more of electrodes 10 to beelectrically connected to one another.

In the embodiment depicted in FIGS. 2-3, test strip 100 contains anintermediate layer 14B which defines a fluid flow path 16. The flow path16 allows fluid to flow from the inlet 18 to the outlet 20 of test strip100.

Test strip 100 may also contain intermediate layers 14A and 14C disposedon opposing planar sides of the intermediate layer 14B. Intermediatelayers 14A and 14C may define one or more sensing areas 22. Individualsensing areas 22 allow fluid traveling through the fluid flow path 16 tocome into contact with individual coplanar electrodes 4, 10 on the firstor the second planar substrate 2, 8. For example, the sensing areasdepicted in FIGS. 1-3 are circular apertures which extend through therespective intermediate layers 14A and 14C. Sensing areas 22 may also befully or partially filled with a chemical/reagent 38 which may reactwith fluid in the fluid flow path 16 and produce a detectable analyte.Alternatively, individual sensing areas 22 may also be defined withoutthe need for intermediate layers 14A and 14C by applying chemicalsand/or reagents directly on a coplanar electrode 4, 10.

Planar substrate 2 is shown in FIGS. 1-3 as having individual sensingareas 22—that are adjacent to the first planar surface 6 of the firstplanar substrate 2—that are associated with respective, individualcoplanar electrodes 4 on the first planar surface 6 (illustrated inFIGS. 1 and 2 in dotted lines as they are not directly visible from thatview). Similarly, individual sensing areas 22 adjacent to the secondplanar surface 12 of substrate 8 are associated with respective,individual coplanar electrodes 10. Those individual coplanar electrodes10 associated with a sensing area 22 are identified as coplanarelectrodes 10A in FIGS. 1-3. The second planar surface 12 of substrate 8further contains coplanar electrodes 10, identified as coplanarelectrodes 10B in the Figures, that are not associated with a sensingarea 22 adjacent to the second planar surface 12 of substrate 8.

As best shown in FIGS. 2-3, one or more, up to all, of the individualcoplanar electrodes 10B of the second planar surface 12 of the secondplanar substrate 8 are electrically connected to a coplanar electrode 4on the first planar surface 6 via a conductive element 24. Conductiveelements 24 extend between the first planar surface 6 and the secondplanar surface 12 without passing through the first planar substrate 2or the second planar substrate 8. The conductive element 24 may alsoextend between the first planar surface 6 and the second planar surface12 without passing through intermediate layer(s) 14. Alternatively,conductive element 24 may pass through one or more, up to all, ofintermediate layer(s) 14. As best shown in FIG. 3, the conductiveelement 24 extends, at least partially, in a direction that issubstantially perpendicular to the first planar surface and the secondplanar surface.

The conductive element 24 may be formed using a variety of methods andmaterials known to a person of ordinary skill in the art. For example,conductive element 24 may be a pogo pin, a wire, or a deposit ofconductive metal. It should also be appreciated that conductive elementmay be affixed to one or both of the first planar substrate 2 and thesecond planar surface 8. For example, an exemplary conductive element 24may be affixed to the first planar substrate 2 prior to the assembly oftest strip 100 such that, when assembled, the conductive element 24comes into electrical contact with exemplary coplanar electrodes 10B (orvice versa). The conductive element 24 may also be affixed to one orboth of to one or both of the first planar substrate 2 and the secondplanar surface 8 after they are arranged in the opposing configurationdepicted in FIGS. 2-3. Additionally, when the conductive element 24passes through one or more, up to all, of intermediate layers 14, theconductive element 24 may be formed in the one or more intermediatelayers 14 prior to arranging the first planar substrate 2 and the secondplanar surface 8 in the opposing configuration depicted in FIGS. 2-3.

As best shown in FIG. 2, the area of the first planar surface 6 of thefirst planar substrate 2 and the intermediate layer(s) 14 are bothsmaller than the second planar surface 12 of the second planar substrate8. When placed in an opposing configuration, the size difference leavesan exposed portion 26 of the second planar surface 12 of the secondplanar substrate 8 uncovered by the first planar substrate 2 as well asintermediate layer(s) 14. The exposed portion 26 contains a portion ofcoplanar electrodes 10 (which may be referred to as coplanar electricalcontacts 28). The coplanar electrical contacts 28 of the exposed portion26 may then be interfaced with an associated medical instrument (such asa meter or reader) by inserting the exposed portion 26 into a receivingslot in the medical instrument (not shown). Stated differently, whenviewing the test strip 100 from above the first planar surface 6 of thefirst planar substrate 2 along the line extending from the first planarsurface 6 of the first planar substrate 2 to the second planar surface12 of the first planar substrate 2, the exposed portion 26 of the secondplanar substrate 8, and the coplanar electrical contacts 28 locatedthereon, are left uncovered by the first planar substrate 2 and theintermediate layers 14.

In yet another alternative embodiment of test strip 100, the firstplanar substrate 2 of test strip 100 can be replaced by a simple lidthat is devoid of electrodes. This configuration would necessitate atest strip 100 in which the second planar substrate 8 contains the onlygroup of coplanar electrodes 10A.

FIGS. 4-6 depict a second illustrative embodiment of a test stripaccording to the inventive concepts disclosed herein. FIG. 4 depicts anexploded view of each layer of test strip 100′. FIG. 5 depicts a topview of test strip 100′. FIG. 6 depicts a side view of test strip 100′along line A-A′. In the following description of test strips 100′, itshould be noted that similar reference numbers to those used to describetest strip 100 in FIGS. 1-3 are intended to refer to similarfeatures—thus avoiding the need to duplicate the detailed description ofthose features.

As best shown in FIGS. 4-5, the first planar substrate 2′ and the secondplanar substrate 8′ have a respective second planar surface 30 and 32which are opposite the first planar surface 6′ and the second planarsurface 12′ of the first planar substrate 2′ and the second planarsubstrate 8′, respectively. One or more, up to all, of the individualcoplanar electrodes 4′ and 10′ of the first planar surface 6′ and thesecond planar surface 12′ of the first planar substrate 2′ and thesecond planar substrate 8′, respectively, are electrically connected toa respective electrical contact 34 and 36 located on the respectivesecond planar surface 30 and 32. Electrical contact(s) 34 may bereferred to as “top side contacts” or “front side contacts” whileelectrical contacts 36 may be referred to as “bottom side contacts” or“back side contacts” (or vice versa depending on the orientation of teststrip 100′). Individual coplanar electrodes 4′ and 10′ can beelectrically connected to a respective electrical contact 34 and 36 in avariety of ways. For example, coplanar electrodes 4′ and 10′ can beelectrically connected to a respective electrical contact 34 and 36using vias, otherwise known as through-holes, that have a conductiveelement 40 located therein that electrically couples respective coplanarelectrodes 4′ and 10′ to electrical contact 34 and 36. Test strip 100′can thus be interfaced with a test strip reading device configured toaccept a test strip with top side contacts 34 and bottom side contacts36.

In yet another alternative configuration, FIG. 7 depicts a side view oftest strip 100″ along a hypothetical line A-A′. In test strip 100″, atop side contact 34 is located on planar substrate 2 while the exposedportion 26″ of the second planar substrate 8″ contains a portion ofcoplanar electrodes 10″ (e.g., coplanar electrical contacts 28″). Thisconfiguration allows the contacts 34 and 28″ of test strip 100″ to beaccessed from the same side (e.g., the top side).

A person of ordinary skill in the art should also appreciate that thereare a variety of methods which may be used to manufacture the test strip100 and 100′, as described above. For example, intermediate layer(s) 14and then the second planar substrate 8 may be formed on the first planarsubstrate 2 (or vice versa).

What is claimed is:
 1. A test strip comprising: a first planar substratewith a plurality of coplanar electrodes on a first planar surface and asecond planar substrate with a plurality of coplanar electrodes on asecond planar surface, wherein the number of the coplanar electrodes ofthe second planar substrate is greater than the number of the coplanarelectrodes of the first planar substrate, and wherein the first planarsubstrate and the second planar substrate are arranged such that thefirst planar surface of the first planar substrate opposes the secondplanar surface of the second planar substrate; an intermediate layerdisposed in between the opposed first planar surface of the first planarsubstrate and the second planar surface of the second planar substrate,the intermediate layer defining a fluid flow path; first sensing areasfor contacting a fluid from the fluid flow path to the coplanarelectrodes of the first planar substrate, which are formed in theintermediate layer; second sensing areas for contacting a fluid from thefluid flow path to some of the coplanar electrodes of the second planarsubstrate, which are formed in the intermediate layer; and a pluralityof conductive elements for electrically connecting respectively coplanarelectrodes of the second planar substrate that are not associated withthe second sensing areas to the coplanar electrodes of the first planarsubstrate, the conductive elements each extending between the firstplanar surface of the first planar substrate and the second planarsurface of the second planar substrate without passing through the firstplanar substrate or the second planar substrate; wherein the test stripcomprises at least a first sensor and a second sensor, each of the firstsensor and the second sensor comprising a first sensing area and anadjacent second sensing area.
 2. The test strip of claim 1, wherein theconductive elements extend without passing through the intermediatelayer.
 3. The test strip of claim 1, wherein the area of the firstplanar surface of the first planar substrate is smaller than the area ofthe second planar surface of the second planar substrate thereby leavinga portion of the second planar surface of the second substrate uncoveredby the first planar surface of the first planar substrate, and whereinrespective portions of the coplanar electrodes of the second planarsubstrate are located in the uncovered portion of the second planarsurface of the second planar substrate.
 4. The test strip of claim 1,wherein the conductive elements extend in a direction that isperpendicular to the first planar surface and the second planar surface.5. The test strip of claim 1, wherein the conductive elements are a pogopin, a wire, or a deposit of conductive metal.
 6. A test stripcomprising: a first planar substrate having a first planar surface and asecond planar surface; a first conductive layer formed on the secondplanar surface of the first planar substrate, the first conductive layerforming a plurality of coplanar electrodes; a second planar substratehaving a first planar surface and a second planar surface; a secondconductive layer formed on the first planar surface of the second planarsubstrate, the second conductive layer forming a plurality of coplanarelectrodes of which the number is greater than the number of thecoplanar electrodes of the first conductive layer; an intermediate layerdisposed in between the second planar surface of the first planarsubstrate and the first planar surface of the second planar substrate,the intermediate layer defining a fluid flow path; and a plurality ofconductive elements electrically connecting respectively the coplanarelectrodes of the first conductive layer to some of the coplanarelectrodes of the second conductive layer without passing through thefirst planar substrate or the second planar substrate, wherein thesecond planar substrate is disposed below the first planar substratealong a line extending from the first planar surface of the first planarsubstrate to the second planar surface of the first planar substrate,the first planar surface of the second planar substrate facing thesecond planar surface of the first planar substrate, the first andsecond planar surfaces of the second planar substrate having a largersurface area than the first and second planar surfaces of the firstplanar substrate, wherein the intermediate layer has first sensing areasand second sensing areas, the first sensing areas contacting a fluidthat flows through the fluid flow path to the coplanar electrodes of thefirst conductive layer, the second sensing areas contacting a fluid thatflows through the fluid flow path to coplanar electrodes of the secondconductive layer that are not associated with the conductive elements,wherein first and second planar surfaces of the intermediate layer andthe first and second planar surfaces of the first planar substrate havea smaller surface area than the first and second planar surfaces of thesecond planar substrate, and thereby, when viewing the test strip fromabove the first planar surface of the first planar substrate along theline, one end portion of the second planar substrate and respectiveportions of the coplanar electrodes of the second conductive layer thatare located in the end portion are uncovered by another layer, thesecoplanar electrode portions being electrically accessible; wherein thetest strip comprises at least a first sensor and a second sensor, eachof the first sensor and the second sensor comprising a first sensingarea and an adjacent second sensing area.